Sanofi-Synthelabo: losing sleep over Ambien competition
Sanofi has filed for US approval to market Ambien CR.
June 25, 2004 4:49 PM GMT (Datamonitor) - Ambien CR is a new version of its top-selling Ambien sleeping drug that is due to lose US patent protection in 2007. Sanofi [SAN.PA] hopes to be able to market the product a full year before the Ambien patent expires, switching patients to Ambien CR to avoid generic competition. However this may not be enough to stave off a dramatic fall in revenues as generics take their slice of the market.
Ambien CR is a controlled release version of Ambien (zolpidem), with patent protection until 2019. It is reported to have an improved pharmacokinetic profile, with only 40-70% of the active ingredient released in the first half hour. The drug is released over a four to six hour period, providing a sustained effect and reducing awakenings to once every five hours, compared to once or twice with Ambien.
Insomnia is a largely undiagnosed condition, and the market is ripe for growth. Sepracor [SEPR] recently announced plans to launch Estorra (eszopiclone) for insomnia in early 2005. Additionally, Neurocrine's [NBIX] agreement with Pfizer for the worldwide development and commercialization of indiplon (instant and delayed release), which is reportedly around ten times more powerful than Ambien, is likely to hit Ambien's market share hard following its US launch, expected mid-2005.
If Ambien CR's approval is successful, it could reach the market in 2005, well before the US patent expiry of Ambien in 2007, allowing Sanofi to switch patients to the new formulation before the entrance of generic competition. However, Ambien CR will attract only a small proportion of treatment naïve patients, with the majority instead favoring either Estorra or indiplon. Furthermore, it is doubtful whether Ambien CR will be enough of an improvement over Ambien to avoid generic competition. However, it seems likely that strong brand loyalty to Ambien in the US, and Sanofi's promotional campaigns, will ensure the Ambien franchise retains its blockbuster status until 2009.
Sanofi should take heart from GSK [GSK.L], which transferred 25% of patients receiving Paxil (paroxetine) to a controlled release version, Paxil CR, before the launch of generic paroxetine. Nevertheless, the Paxil franchise declined significantly post patent expiry. Similarly, approval for Ambien CR may stave off losses for a short while, but both new and generic competition will undoubtedly catch up with the Ambien franchise sooner than Sanofi would like.
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